Health authorities have identified three more people who have contracted Legionnaires' disease in Sydney's CBD.
Two of the patients were within the CBD region between late February and early this month, NSW Health said in a statement.
That brings the total number of cases linked to the outbreak to eight.
The third patient, who has now recovered, contracted the disease in December.
The state's health department on Thursday said four men were being treated for the disease after spending time in the Sydney Town Hall area.
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It updated the number of previously identified patients to five on Friday and said three of them had recovered while the other two remained in hospital.
It's thought the victims may have contracted the disease from a contaminated cooling tower.
Legionnaires' disease is a type of pneumonia caused by a bacterial infection of the lungs that can develop after someone breathes contaminated water vapour or dust.
The search for the source of the outbreak originally focused on the Druitt, Market, Sussex and Pitt street area of the city.
"That search area has now been expanded further east to Elizabeth Street," a health department spokeswoman said.
NSW Health and the City of Sydney have been contacting building owners and managers to remind them to properly maintain cooling towers.
Anyone who lives, visits or works in the Town Hall area and develops symptoms of legionnaires' disease has also been urged to visit their doctor.
